For centuries people have worked to solve the problem of securing eyeglasses comfortably on a wearer's head. There is a natural tendency for glasses to slip down the wearer's nose and face, from their optimal location with the lenses positioned in front of the wearer's eyes. The problem is exacerbated when glasses are worn during vigorous activities such as running or cycling, or when the wearer has fluid such as sweat, make-up, or lotion around the eyes and upper part of the nose where glasses typically rest.
The most common device used today to secure eyeglasses on a person's head is a strap worn behind the wearer's head, connecting distal tips of the two eyeglass temples. However, eyeglass straps are not always preferred or appropriate. Some people do not want the visibility of a strap. At work or formal events, an eyeglass strap may be distracting or may appear too casual. Other times a strap may be undesirable because of the effect it has on the wearer's hair. Another problem with eyeglass straps is that they usually require two hands to remove. Eyeglasses with straps also can be difficult to fit into an eyeglass case. Thus, there is a need for alternatives to an eyeglass strap for retaining eyeglasses on a person's head.
A number of eyeglass retainers have been designed that use a narrow semirigid hook mechanism behind the ear to resist forward movement of the temple. For example, some eyeglasses have "wrap-around" temples with end portions that are thin wire gauge extenders curved to wrap around the back of the wearer's ear. The wrap-around temple is designed to fit in the crease where the ear and head connect. However, temples with permanent wrap around tips rarely fit in the right spot because the eyeglass frames are usually not customized. If the wrap-around portion is too far back then the glasses slide forward before the hook meets the ear. If the wrap-around portion is too far forward then the spring-like wire exerts excessive pressure behind the ear causing discomfort.
Modifications of traditional wrap-around temples are disclosed in U.S. Pat. No. 2,626,538 and U.S. Pat. No. 5,002,381, each of which discloses an add-on accessory for an eyeglass temple including a tube portion that slides over the distal tip of a temple for placement along the temple in relation to the wearer's ear. A hook member extends down from the tube portion presenting a concave surface for positioning in the crease behind the wearer's ear and resisting forward movement of the eyeglasses.
An inherent problem with hook-shaped eyeglass retainers is that functionally they rely on direct forward pressure applied behind the ear in a relatively small and highly sensitive area where the ear meets the head. The hook-shaped retainer must be relatively stiff in the front-to-back direction, otherwise, the retainers fail to hold the eyeglasses in place. Some hook-shaped retainers may function acceptably for the purpose of securing eyeglasses, but over time they cause irritation behind the ear, which is probably why such retainers are not more widely used today.
Another problem with accessory retainers such as the ones disclosed in U.S. Pat. Nos. 2,626,538 and 5,002,381 is that the tube portions are insufficiently flexible to fit over a wide range of temple dimensions. The thickness and shape of eyeglass temples vary dramatically. Eyeglass temples may be small gauge wire extensions with a round cross-section, as in aviator glasses, or they may be large plastic braces such as the temples of a RAY BAN WAYFARER.RTM.. The tube portions of prior accessory retainers such as those mentioned above are not versatile enough to fit on temples that vary over a wide range of cross-sectional dimensions.
Another approach to retaining eyeglasses is to use temples that clamp the head. This design may work satisfactorily for extremely lightweight eyewear on some head sizes. However, the clamping force required to secure most glasses for extended periods will eventually cause discomfort. It is also difficult to pre-set a clamping force that will achieve the retention goal comfortably on a wide range of head sizes. This is a significant limitation because most eyeglass frames are not customized for a particular person.
Even though the problem of securing eyeglasses has been worked on diligently by many people for many years, a need still exists for a comfortable, flexible, inexpensive, universal eyeglass retainer that is unobtrusive and does not require an around-the-head tensioning strap.